/* Test of posix_spawn() function with an inherited file descriptor 1.
Copyright (C) 2008-2023 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
/* Written by Bruno Haible , 2020. */
/* Test whether passing a file descriptor open for writing, including the
current file position, works. */
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define CHILD_PROGRAM_FILENAME "test-posix_spawn-inherit1" EXEEXT
#define DATA_FILENAME "test-posix_spawn-inh1-data.tmp"
static int
parent_main (void)
{
FILE *fp;
char *argv[3] = { CHILD_PROGRAM_FILENAME, "-child", NULL };
int err;
pid_t child;
int status;
int exitstatus;
/* Create a data file with specific contents. */
fp = freopen (DATA_FILENAME, "wb", stdout);
if (fp == NULL)
{
perror ("cannot create data file");
return 1;
}
fwrite ("Halle X", 1, 7, fp);
if (fflush (fp) || fseek (fp, 6, SEEK_SET))
{
perror ("cannot prepare data file");
return 1;
}
/* Test whether the child writes to fd 1 at the current file position. */
if ((err = posix_spawn (&child, CHILD_PROGRAM_FILENAME, NULL, NULL, argv, environ)) != 0)
{
errno = err;
perror ("subprocess failed");
return 1;
}
status = 0;
while (waitpid (child, &status, 0) != child)
;
if (!WIFEXITED (status))
{
fprintf (stderr, "subprocess terminated with unexpected wait status %d\n", status);
return 1;
}
exitstatus = WEXITSTATUS (status);
if (exitstatus != 0)
{
fprintf (stderr, "subprocess terminated with unexpected exit status %d\n", exitstatus);
return 1;
}
if (fclose (fp))
{
perror ("cannot close data file");
return 1;
}
/* Check the contents of the data file. */
fp = fopen (DATA_FILENAME, "rb");
if (fp == NULL)
{
perror ("cannot open data file");
return 1;
}
char buf[1024];
int nread = fread (buf, 1, sizeof (buf), fp);
if (!(nread == 11 && memcmp (buf, "Halle Potta", 11) == 0))
{
fprintf (stderr, "data file wrong: has %d bytes, expected %d bytes\n", nread, 11);
return 1;
}
if (fclose (fp))
{
perror ("cannot close data file");
return 1;
}
/* Clean up data file. */
unlink (DATA_FILENAME);
return 0;
}
static int
child_main (void)
{
/* Write to STDOUT_FILENO. */
fwrite ("Potta", 1, 5, stdout);
/* No 'fflush (stdout);' is needed. It is implicit when the child process
exits. */
return 0;
}
static void
cleanup_then_die (int sig)
{
/* Clean up data file. */
unlink (DATA_FILENAME);
/* Re-raise the signal and die from it. */
signal (sig, SIG_DFL);
raise (sig);
}
int
main (int argc, char *argv[])
{
int exitstatus;
if (!(argc > 1 && strcmp (argv[1], "-child") == 0))
{
/* This is the parent process. */
signal (SIGINT, cleanup_then_die);
signal (SIGTERM, cleanup_then_die);
#ifdef SIGHUP
signal (SIGHUP, cleanup_then_die);
#endif
exitstatus = parent_main ();
}
else
{
/* This is the child process. */
exitstatus = child_main ();
}
return exitstatus;
}